1. Field of the Invention
The present invention relates to an elongate molding member to be used as a body component for an automobile and the like, as well as a method of producing such a molding member.
2. Description of the Related Art
Typically, various automobile body components include elongate molding members often formed of suitable synthetic resin material, such as windshield moldings, back window moldings, front and/or rear bumper moldings, drip moldings, body side moldings, pillar moldings, belt moldings, etc. For refining the ornamental appearance of the automobile, there have been various proposals and, among others, Japanese Utility Model Application Laid-open Publication No. 53-111,928 discloses a molding member with its exterior including at least one strip-like ornamental portion having a metallic luster and made different in color from the remaining portions.
More particularly, the above-mentioned proposal provides a method of producing elongate molding members wherein an elongate core element with at least one outer surface portion of a metallic luster is applied with a protective cover film along that region which corresponds to the strip-like ornamental portion of the product to be disclosed. So prepared core element is subsequently fed to an extrusion die by which synthetic resin material is co-extruded around the core element to form an elongate composite body. At least one slit is then formed in the composite body at a predetermined location which corresponds to the longitudinal edge of the cover film, so as to facilitate separation of the cover film and to disclose the strip-like ornamental portion of the core element with the metallic luster.
The molding member produced as above has a uniform cross-sectional shape throughout the entire length thereof, with a constant width of the differently colored ornamental portion of the core element which is exposed outside. This means that it is not possible, by the above-mentioned known method, to produce molding members with the exposed portion of the core element having a width which varies longitudinally of the molding member to satisfy various ornamental design requirements.
In order to produce the co-extruded molding members having a differently colored ornamental portion with a longitudinally variable width, the synthetic resin material extruded around the core element may be separated and removed from the composite body with a longitudinally variable width corresponding to the ornamental portion of the core element. However, in order to facilitate the separation and removal of the synthetic resin material from the composite body to disclose the strip-like ornamental portion of the core element, the synthetic resin material would tend to be subjected to unintentional separation from the remaining portions of the core elements whereby a stable product cannot be obtained.
As an alternative approach, the molding member may be formed of a plurality of separate elements including one for the ornamental portion, which may be connected into an integral body with a so-called insert-injection process. With such a process, however, undesirable burrs may be formed along the interface of the neighbouring elements substantially deteriorating the appearance of the product.